Drive mechanism with noise reduction

Patent metadata

Field	Value
Publication number	US-11666709-B2
Application number	US-201816771151-A
Country	US
Kind code	B2
Filing date	Dec 20, 2018
Priority date	Dec 21, 2017
Publication date	Jun 6, 2023
Grant date	Jun 6, 2023

Abstract

A drive mechanism for a drug delivery device with a reduced operating loudness includes a dose selector, a housing, and a ratchet with a gear element comprising a plurality of gear teeth connected with the dose selector and a pawl element rotationally constrained to the housing comprising at least one pawl tooth. The at least one pawl tooth engages with the gear teeth and is located opposite to the gear teeth. One of the gear element and the pawl element moves forth and back relative to the other element of the gear and pawl elements along a first direction for de-engagement and re-engagement of the opposite gear teeth and at least one pawl tooth when the gear element rotates relative to the housing during dose setting using the dose selector. The pawl element and/or gear element comprises a noise reduction characteristic at a surface which dampens the noise produced.

First claim

The invention claimed is:

1. A drive mechanism for a drug delivery device, the drive mechanism comprising:
a dose selector; and
a housing and a ratchet with a gear element comprising a plurality of gear teeth connected with the dose selector and a pawl element rotationally constrained to the housing comprising at least one pawl tooth,
wherein the at least one pawl tooth engages with the plurality of gear teeth and is located opposite to the plurality of gear teeth,
wherein one of the gear element and the pawl element moves forth and back relative to the other element of the gear element and the pawl element along a first direction for de-engagement and re-engagement of opposite gear teeth and the at least one pawl tooth when the gear element rotates relative to the housing during dose setting using the dose selector,
wherein one or both of the pawl element and the gear element comprises a noise reduction characteristic at a surface which dampens noise produced when a tooth or teeth of a respective other element of the pawl element and the gear element moves or move back into re-engagement when the gear element rotates relative to the pawl element,
wherein the noise reduction characteristic comprises at least one of:
a helical form of the plurality of gear teeth and a corresponding helical form of the at least one pawl tooth,
a beveled form of the plurality of gear teeth and a corresponding beveled form of the at least one pawl tooth, and
an elastomeric material surface layer or an elastomeric material body at a predefined section of one or both of at least part of the plurality of gear teeth and the at least one pawl tooth.

2. The drive mechanism of claim 1 , wherein the first direction is a longitudinal direction of the drive mechanism or a direction radial to the longitudinal direction.

3. The drive mechanism of claim 1 , wherein the pawl element is located at a front face of a drive sleeve.

4. The drive mechanism of claim 3 , wherein the drive sleeve is rotationally constrained with respect to the housing during dose setting.

5. The drive mechanism of claim 1 , wherein the plurality of gear teeth are located at a front face of a clutch plate that is rotationally constrained with respect to the dose selector during dose setting.

6. The drive mechanism of claim 1 , wherein the noise reduction characteristic comprises grease located at the surface of the plurality of gear teeth or the at least one pawl tooth at an inner section.

7. The drive mechanism of claim 1 , wherein the noise reduction characteristic comprises an annular collar attached at the gear element or at the pawl element with a plurality of pawl teeth.

8. The drive mechanism of claim 7 , wherein the annular collar comprises a plurality of collar teeth formed by an elastomeric material.

9. The drive mechanism of claim 8 , wherein the collar teeth form an outer section of at least a part of the plurality of gear teeth or the plurality of pawl teeth.

10. The drive mechanism of claim 1 , wherein the noise reduction characteristic comprises an internal bung attached at the gear element or at the pawl element with a plurality of pawl teeth.

11. The drive mechanism of claim 10 , wherein the internal bung comprises a plurality of bung teeth elements formed by an elastomeric material.

12. The drive mechanism of claim 11 , wherein the plurality of bung teeth elements forms the at least one of the plurality of gear teeth or the plurality of pawl teeth.

13. The drive mechanism of claim 12 , wherein the plurality of bung teeth elements and the plurality of hoop teeth elements comprise one of a straight tooth corresponding in a form to a tooth, a notched section, a crab claw section, and a pebble projection.

14. The drive mechanism of claim 1 , wherein the noise reduction characteristic comprises a damping hoop attached at the gear element or at the pawl element with a plurality of pawl teeth.

15. The drive mechanism of claim 14 , wherein the damping hoop comprises a plurality of hoop teeth elements formed by an elastomeric material.

16. The drive mechanism of claim 15 , wherein the plurality of hoop teeth elements forms the at least one of the plurality of gear teeth or the plurality of pawl teeth.

17. The drive mechanism of claim 16 , wherein the plurality of bung teeth elements and the plurality of hoop teeth elements comprise one of a straight tooth corresponding in a form to a tooth, a notched section, a crab claw section, and a pebble projection.

18. A drug delivery device comprising:
the drive mechanism comprising:
a dose selector; and
a housing and a ratchet with a gear element comprising a plurality of gear teeth connected with the dose selector and a pawl element rotationally constrained to the housing comprising at least one pawl tooth,
wherein the at least one pawl tooth engages with the plurality of gear teeth and is located opposite to the plurality of gear teeth,
wherein one of the gear element and the pawl element moves forth and back relative to the other element of the gear element and the pawl element along a first direction for de-engagement and re-engagement of opposite gear teeth and the at least one pawl tooth when the gear element rotates relative to the housing during dose setting using the dose selector,
wherein one or both of the pawl element and the gear element comprises a noise reduction characteristic at a surface which dampens noise produced when a tooth or teeth of a respective other element of the pawl element and the gear element moves or move back into re-engagement when the gear element rotates relative to the pawl element,
wherein the noise reduction characteristic comprises at least one of:
a helical form of the plurality of gear teeth and a corresponding helical form of the at least one pawl tooth,
a beveled form of the plurality of gear teeth and a corresponding beveled form of the at least one pawl tooth, and
an elastomeric material surface layer or an elastomeric material body at a predefined section of one or both of at least part of the plurality of gear teeth and the at least one pawl tooth.

19. The drug delivery device of claim 18 , wherein the first direction is a longitudinal direction of the drive mechanism or a direction radial to the longitudinal direction.

20. The drug delivery device of claim 18 , wherein the pawl element is located at a front face of a drive sleeve.

Assignees

• Sanofi Sa

Inventors

• Collings Ralph Donald Quentin
• Coop James Robert
• West James Anthony
• Gilmore Stephen Francis
• Higgins Daniel David
• Teucher Mark Digby
• Carroll Jack
• Quigg Timothy Robin
• Stein Laura
• Blancke Stefan
• Sladen Sophie

Classifications

• A61M5/31535

  Means improving security or handling thereof, e.g. blocking means, means preventing insufficient dosing, means allowing correction of overset dose · CPC title

• A61M5/31553

  without axial movement of dose setting member · CPC title

• A61M2205/0216

  Materials providing elastic properties, e.g. for facilitating deformation and avoid breaking · CPC title

• A61M2005/3143

  Damping means for syringe components executing relative movements, e.g. retarders or attenuators slowing down or timing syringe mechanisms · CPC title

• A61M5/31541

  Means preventing setting of a dose beyond the amount remaining in the cartridge · CPC title